114 ECONOMIC ZOOLOGY 



render their flesh unwholesome." According to Dr. Geogaghan (116) 

 once medical officer of the Turk Islands there are two forms of disease 

 produced by these fish: one, like ordinary ptomaine poisoning, coming 

 on 10 to 20 hours after eating the fish, acute but yielding quickly to 

 treatment; the other producing slow dull pains, especially of the joints, 

 coming on from 2 to 6 days after eating the fish and lasting many 

 months. The same fish that cause these diseases in the Turk Islands 

 and Bahamas are eaten at Key West and Bermuda where the poisoning 

 is unknown. The reason for this Mowbray explains as follows: 



"After observing the conditions and manner in which the fish are handled, 

 I have reached the conclusion that the reason they are poisonous, in one region 

 and not in another, is that in Bermuda and Key West almost all fishing 

 boats have live-wells, and therefore usually bring their fish to market alive, 

 while in the Turk Islands and the Bahamas the fish are killed and allowed 

 to remain in the sun until the shore is reached, sometimes 5 or 6 hours 

 after they are caught. All of the fishes considered poisonous are of soft 

 flesh and rich in gastric juices, and are therefore the most likely to decay 

 quickly; and, when eaten in a partially decayed condition, cause ptomaine 

 poisoning. Naturally, some are more poisonous than others. Those caught 

 in the morning are exposed to the sun rays much longer, and are therefore 

 much more decomposed." 



It would seem from this that possibly the poisonous character of 

 fishes is largely a matter of their being more or less decomposed, though 

 it is thought by some to be due to the character of the food eaten at 

 different seasons. 



The most^ important of the world's food-fishes are said by some to 

 be the herrings. This family (Clupeidae) includes considerably over 

 100 species and is probably more numerous in individuals than any 

 other family of fishes. 



The common herring (Clupea harengus] is one of the most important 

 of all food fishes; it is caught in nets in enormous numbers along the 

 Atlantic coasts of both North America and Europe. For example at 

 Port Deposit, Maryland, a fishing station on the Susquehanna River, 

 these fish are caught in huge seines, hundreds of feet long, which are 

 hauled in by an engine or by horse-power upon a floating dock; 100,000 

 fish may be brought in at one time in this way. They are cleaned, 

 salted and packed in barrels on the spot so that they have no oppor- 

 tunity to decay in the least. It has been estimated that at least 

 10,000,000,000 herring are caught annually by British and American 



